On Tue, Apr 11, 2017 at 06:47:28AM -0700, John Muir wrote: > > On Apr 10, 2017, at 8:42 AM, Rob Herring <r...@kernel.org> wrote: > > > > On Tue, Apr 04, 2017 at 12:20:34PM -0700, John Muir wrote: > >> +MAX31760 fan controller > >> +----------------------- > >> + > >> +This device supports I2C only. Many properties of this device are > >> configurable > >> +thorugh the hwmon interface. See also Documentation/hwmon/max31760. > > > > I really think we need to describe the fans as separate nodes and > > preferably with a common binding. This is the second fan controller > > binding recently[1]. > > > > Features of the "hwmon interface" are not relevant to the binding. > > Bindings describe h/w. > > It seems to me that referring to the hwmon interface is only helpful. You are > suggesting removing those sentences? If so, can I add a link to the data > sheet? >
Devicetree properties are supposed to be operating system independent. Any mention of how access to the device is implemented on a given operating system is out of scope for this document. Guenter > > > >> +Optional node properties: > >> +- maxim,fan1-enabled - 1 to enable, 0 to disable. Default: 1. > >> +- maxim,fan2-enabled - 1 to enable, 0 to disable. Default: 1. > >> +- maxim,fan1-label - String: Hwmon fan1_label. > >> +- maxim,fan2-label - String: Hwmon fan2_label. > > > > Perhaps 2 fan sub nodes. reg for fan number, status for enabled, and > > label for label. > > OK. > > Right now a fan’s number of pulses and the PWM frequency are configured using > the hwmon sysfs interface (which defines standard controls for those), but as > those are characteristics of the hardware, should they also be configured via > the device tree binding? > > >> +- maxim,pwm-zero-fan-can-fail - 0: Fan failure detection disabled > >> when PWM is > >> + ramping to 0%. > >> + 1: Fan failure detection enabled for all PWM > >> + values. > >> + Default: 0. > > > > All these can be boolean… > > OK. The only issue I see is when the default is ‘true’ in the device, but > I’ll try to avoid that. Sometimes I wish that you could set a boolean to > false in DTS files. > > > > >> +- maxim,temp1-label - String: Hwmon temp1_label. > >> +- maxim,temp2-label - String: Hwmon temp2_label. > >> +- maxim,temp2-ideality - Set ideality factor for the remote > >> temperature > >> + sensor. Integer with range 0 to 63, > >> + representing a multiplication factor of 0.9844 > >> + to 1.0489. Default: 24 (1.0080). > > > > No maxim,temp1-ideality? > No - the device only lets you set the ideality of the ‘external' temperature > sensor. I guess if there is an ideality for the internal temperature sensor, > it would be hard-wired as a characteristic of the part that was used. > > > Not sure what to do with these, but perhaps > > also as sub-nodes. Surely we have some bindings already for devices with > > multiple temp sensors. Don't invent something custom here. > > I’ll look into it. > > What is the best way to distinguish between ‘fan’ and ‘temp’ sub-nodes? Do I > require a ‘compatible’ string? > > Thanks! > > John. > > -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
